A recessed luminaire may include a recessed housing can that is mounted in a ceiling using a plaster frame. Further, the recessed luminaire may include a light source and a finishing section that are configured to fit inside the recessed housing can. The finishing section may include a main body, one or more reflectors, and a trim ring that is integral to the main body. In one example, the finishing section may be retained within the recessed housing can using a friction type retention system, e.g., friction blades. Typically, to install the finishing section in the recessed housing can, the finishing section may be inserted into an opening of the recessed housing can till the friction blades of the finishing section engage the inner surface of the recessed housing can and the trim ring of the finishing section engages the ceiling to eliminate gaps between the trim ring of the finishing section and the ceiling. However, after installation, the plaster frame and/or the recessed housing can of the recessed luminaire may settle creating an undesirable gap between the trim ring of the finishing section and the ceiling.
For example, as illustrated in FIGS. 1 and 2, a plaster frame assembly 106 may include hanger bars 103 and a base plate 105 that retains a recessed housing can 102. The hanger bars 103 may be coupled to the base plate 105. Further, the hanger bars 103 may be fastened to the rafters or joists 101 to retain the plaster frame assembly 106 and the recessed housing can 102 in a space 110 between a lower finished surface ceiling 104 (herein ‘lower ceiling 104’) and an upper structural ceiling 107 (herein ‘upper ceiling 107’). Before installation of a finishing section 304 in the recessed housing can 102, as illustrated in FIGS. 1 and 2, the plaster frame assembly 106 may be disposed in the space 110 such that the base plate 105 of the plaster frame assembly 106 rests on and engages a top surface 204 of the lower ceiling 104 without any gaps in between the base plate 105 and the top surface 204 of the lower ceiling 104. However, when a finishing section 304 having a trim ring 306 (shown in FIG. 3) is inserted into the recessed housing can 102 such that the trim ring 306 engages the bottom surface 206 of the lower ceiling 104, the hanger bars 103 of the plaster frame assembly 106 that holds the base plate 105 and the recessed housing can 102 may bend upwards because of the friction between the friction blades of the finishing section 304 and the inner surface of the recessed housing can 102. As the hanger bars 103 bend upwards, as illustrated in FIGS. 3 and 4, the base plate 105 that is coupled to the hanger bars 103 may also move upwards creating a gap 402 in between the base plate 105 and the top surface 204 of the lower ceiling 104.
Once the finishing section 304 is installed within the recessed housing can 102, the hanger bars 103 and the base plate 105 of the plaster frame assembly 106 gradually revert back to their default position. Consequently, the recessed housing can 102 coupled to the base plate 105 and the finishing section 304 installed in the recessed housing can 102 also shift downward to their default position, as illustrated in FIG. 5. When the finishing section 304 that is coupled to the recessed housing can 102 shifts downward, a gap 502 may be created in between the trim ring 306 of the finishing section 304 and a bottom surface 206 of the lower ceiling 104 as illustrated in FIG. 5. Said gap 502 between the trim ring 306 of the finishing section and the ceiling 104 may be undesirable and unsightly.
Further, in other examples, conventional plaster frame assemblies may not provide an air-tight sealing of the recessed housing cans coupled thereto. Air leakage through openings that are formed in the recessed housing cans and through other openings that are formed when the recessed housing cans are installed in the ceiling using the conventional plaster frame assemblies may negatively impact an energy efficiency of a building in which the recessed housing cans are installed to provide recessed lighting. Further, such openings may expose the components disposed in the recessed housing can, such as the light source, to environmental factors (dust, dirt, etc.) which in turn reduces an efficiency and/or durability of the recessed luminaires.